Here is, 1. The prayer the psalmist puts up for the happiness of those that are sincere and constant (Psa 125:4): Do good, O Lord! unto those that are good. This teaches us to pray for all good people, to make supplication for all saints; and we may pray in faith for them, being assured that those who do well shall certainly be well dealt with. Those that are as they should be shall be as they would be, provided they be upright in heart, that they be really as good as they seem to be. With the upright God will show himself upright. He does not say, Do good, O Lord! to those that are perfect, that are sinless and spotless, but to those that are sincere and honest. God's promises should quicken our prayers. It is comfortable wishing well to those for whom God has engaged to do well. 2. The prospect he has of the ruin of hypocrites and deserters; he does not pray for it (I have not desired the woeful day, thou knowest), but he predicts it: As for those, who having known the way of righteousness, for fear of the rod of the wicked, basely turn aside out of it to their wicked ways, use indirect ways to prevent trouble or extricate themselves out of it, or those who, instead of reforming, grow worse and worse and are more obstinate and daring in their impieties, God shall send them away, cast them out, and lead them forth with the workers of iniquity, that is, he will appoint them their portion with the worst of sinners. Note, (1.) Sinful ways are crooked ways; sin is the perverting of that which is right. (2.) The doom of those who turn aside to those crooked ways out of the right way will be the same with theirs who have all along walked in them, nay, and more grievous, for if any place in hell be hotter than another that shall be the portion of hypocrites and apostates. God shall lead them forth, as prisoners are led forth to execution. Go, you cursed, into everlasting fire; and these shall go away; all their former righteousness shall not be mentioned unto them. The last words, Place upon Israel, may be taken as a prayer: "God preserve his Israel in peace, when his judgments are abroad reckoning with evil-doers." We read them as a promise: Peace shall be upon Israel; that is, [1.] When those who have treacherously deserted the ways of God meet with their own destruction those who faithfully adhere to them, though they may have trouble in their way, shall have peace in the end. [2.] The destruction of those who walk in crooked ways will contribute to the peace and safety of the church. When Herod was cut off the word of God grew, Act 12:23, Act 12:24. [3.] The peace and happiness of God's Israel will be the vexation, and will add much to the torment, of those who perish in their wickedness, Luk 13:28; Isa 65:13. My servants shall rejoice, but you shall be ashamed.

Do good, O Lord, unto those that be good,.... That are made so by the Spirit and grace of God; for none are naturally good, but evil; only such who are regenerated and made new creatures, who have a good work of grace begun in them; who have the good Spirit of God, and his good graces, and the good word of God in them, and are filled with all goodness; and which is known by the good fruits which they bear, or the good works done by them. For these the psalmist prays the Lord would do good to them, not only in a providential way, as he does to all; but in a way of special grace, bestowing the blessings of his goodness on them, and causing all things to work for their good: and as saints should pray for one another, or supplication should be made for all saints, such a prayer as this may be the prayer of faith; for it is not to be doubted but God will do good to those he makes good. Aben Ezra says this may be considered either as a prayer or a prophecy; it may have respect unto the church in the latter day, and to the good things spoken of concerning it; which God will accomplish in due time, and should be prayed for; see Psa 51:18;

and to them that are upright in their hearts; which is a further description of good men, from the integrity and sincerity of their hearts; who do all they do before God and men, in the uprightness of their souls, cordially and sincerely, from right principles, and with right views.